1. Field of the Invention
The present invention relates to a dual-filtration oil system, kit and apparatus which may be used on air-cooled or liquid-cooled engines in vehicles, as well as in some other applications such as in industrial settings, etc. The primary application for the present invention is on an internal combustion engine. More particularly, the present invention relates to a visually attractive dual-filtration oil filter system, kit and apparatus, including filter covers and manifolds which are designed to maximize the cooling effect obtained from air flowing around components of the system, for improving cooling efficiency and enhancing aesthetic appearance.
2. Description of the Background Art
Certain types of vehicles have air-cooled engines. Motorcycles, such as those manufactured by the Harley Davidson Motorcycle Company of Milwaukee, Wis., have large displacement, four stroke, air-cooled engines. It is well known that these engines have an oil pump that circulates oil through the engine, to lubricate the components and to carry away the accumulated heat of combustion and friction. To assure proper circulation and lubrication, it is imperative that proper oil pressure be maintained. A significant drop in oil pressure can result in engine damage.
It is well known with engines of this type that they have replaceable “spin-on” oil filters that are removably attached to the engine. Typically, a filter mount fitting is provided on a portion of the engine block, the filter mount fitting including a threaded port to accommodate a threaded bore in the filter. The threaded port of the filter mount fitting has an axial bore, through which oil from the filter is returned to the engine for re-circulation by the oil pump.
The filter has a threaded center bore formed therein, such that the filter can be installed on or removed from the threaded port on the engine at appropriate times. One or more openings are disposed about the port on the engine block, through which engine oil, delivered by the oil pump, is supplied to the filter. The filter removes harmful contaminants from the oil, and also helps to dissipate heat from the oil, mostly via convection heat transfer as air flows around exterior surfaces of the filter.
With continuing reference to air-cooled engine of the type described above, the primary cooling of this type of engine is carried about by air movement past integral cooling fins provided on the cylinder block. When the vehicle is moving, forced convection heat transfer occurs to carry away heat, provided that the ambient air moving past the fins is sufficiently cool.
When the vehicle is stopped with its engine running, and particularly in elevated ambient conditions such in extreme heat and humidity, the temperature of the oil may rise to such a high level that oil pressure may drop to a dangerously low level. In those circumstances, the operator of the vehicle must turn off the engine, or risk damage to internal engine components. The foregoing is particularly true for vehicles which may be stopped in traffic, or involved in slow moving, stop-and-go traffic conditions. Under these conditions and in the engines of this type described above, insufficient cooling takes place to maintain proper oil pressure.
A drawback of prior oil filtering and cooling systems is that their close proximity to the engine does not allow for efficient cooling of the oil. Heat from the engine is transferred to the immediate environment surrounding the engine, particularly in stagnant conditions when the motorcycle is not moving. This increases ambient temperature conditions about the oil cooler, thus affecting the efficiency thereof.
A number of different devices are known for utilizing airflow to cool oil during or close to a time while the oil is being passed through a filter. Some examples of known devices include U.S. Pat. No. 5,363,823 to Gittelin, U.S. Pat. No. 4,831,980 to Nasu et al., U.S. Pat. No. 5,653,206 to Spurgin, U.S. Pat. No. 5,701,853 to Takahashi, European Patent EP 0969185AL to Schanz and Canadian Patent 1,147,273 to Preisler et al.
Although the known devices have some utility for their intended purposes, a need still exists in the art for an improved dual oil filtering system, kit, and apparatus for use on internal combustion engines. In particular, there is a need for an improved dual-filtration oil filtering system, kit, and apparatus for an engine that is visually attractive, and efficiently cools the oil so that the engine will not overheat or suffer damage.